1. The Field of the Invention
The present invention relates to dip tube anchors and related containers in which a dip tube is disposed.
2. The Relevant Technology
Dip tubes are commonly used in association with various types of containers for withdrawing a fluid from the containers. A dip tube simply comprises a tube having a first end that is lowed into a container so as to be disposed toward the bottom of the container. A second end of the tube extends out through the top of the container. By applying one of various different types of forces, the fluid can be selectively removed from the container by entering through the first end of the dip tube and exiting through the second end of the dip tube. The first end of the dip tube is typically located near the bottom of the container so as to maximize removal of all of the fluid from the container, thereby minimizing waste of the fluid.
Although dip tubes as discussed above are commonly use, they have a number of shortcomings. For example, dip tubes are commonly formed from flexible polymeric tubing that is typically coiled upon formation. Dip tubes made from such tubing have a natural tendency to partially coil or bend when disposed within the container. As a result, the first end of the dip tube is spaced upward, away from of the bottom of container. The dip tube is thus unable to remove all of the fluid from the container without further manipulation of the container and/or the dip tube. Where the fluid is highly expensive, such as is commonly found in the biotechnology industry, this shortcoming can be a significant detriment.
In one attempt to overcome the above problem, an anchor is used to secure the dip tube to the bottom of the container. The anchor comprises a flat plate from which a tubular spout projects. A first opening is formed on the side of the spout next to the pate. A second opening is formed on the upper free end of the spout. A passageway extends between the two openings. The plate is secured on the interior surface of the floor of the container so that the stem projects up into the container. The first end of the dip tube is coupled with the upper end of the spout. As such, fluid enters through the first opening on the spout and travels up through the spout and into the dip tube.
Although use of such anchors solves some problems, it creates others. For example, many of the containers used to hold the fluid comprise a collapsible polymeric bag. An adhesive is used to secure the plate of the anchor to the floor of the bag. The use of an adhesive inside of the bag, however, is problematic in that it increases the risk that unwanted contaminates could leech from the adhesive into the fluid. Furthermore, acceptable adhesives are often found to have insufficient strength, thereby resulting in the anchor breaking free from the bag during manufacture, transport or use.
In addition, securing the plate of the anchor to interior surface of the floor of the bag is a difficult manufacturing step to automate. Thus, the process typically requires that the anchor be manually secured to the bag, thereby slowing production and increasing cost. Finally, because the spout of the anchor projects above the plate which is mounted on the floor of the bag, the first opening on the spout is still not the low point on the floor of the container. As such, the dip tube is still unable to capture a portion of the fluid within the container.
Accordingly, what is needed in the art are improved ways for enabling a dip tube to maximize the removal of fluid from a container.